O-alkyltyrosine esters



United States Patent 2,833,810 O-ALKYLTYROSINE ESTERS Henry MarcellKissman, 'Nanuet, N. Y., Joseph Peter 5 Joseph, 'Clilfside Park, N. 1., and Bernard'Randall Baker, Birmingham, Ala., assignors to American Cyan- .amid'Company, New York, N. Y., a corporation of Delaware 'No Drawing. Application-March 5, 1956 Serial No. 569,225

6 Claims. .(Cl. 260-471) This inventionrelates to new organic-compounds and more particularly is concerned with novel O-alkyl tyrosine esters whichmay be. represented by the following general ..formula:

ll mo-Q-cm-orno-o R1 NHa wherein R is a member of the group consistingof aucyl radicals, alkenyl radicals such as S-methyl-S-hexenyl alkoxyalkyl radicals such as Z-methoxyethyl, etc., halosubstituted lower alkyl radicals such as chloroethyl, chlorobutyl, etc., cycloalkyl radicals, such as cyclohexyl, mononuclear aryl substituted .lower alkyl radicals ,such as 2,833,810 Pa-tented May 6, 1958 ice ."2 in agar and sterilized. The molten agar was poured into'plates, allowed to harden and a standard culture of each ofthe organisms against which'the Samples were to 'be testedwaslstreaked'on,the. surface of'the plates. Alternatively the samples were mixed with .5, ml. of ethanol and added to 12 ml. of sterile 5% Jaqueoussolution of sodium carboxymethylcellulose. Samples of the resulting solution or suspension werethen prepared in serial dilutions and to these samples was added sterile molten .agar aseptically. It was found that thenew compounds completely inhibit he growth 'of the above mentioned microorganisms in concentrations as low as 0.008 mgm. per ml. of agar.

The compounds of this invention may be prepared by reacting an, appropriate N-formyltyrosine with a suitable alkylating agent, such as 'dimethyl sulfate, or an alkyl .halide -e. g. methyl. iodide, in the presence of sodium \methoxideinmethanol. Whendimethyl sulfate or methyl iodide areused obviously only-O-methyl-N-formyltyrosine is produced. The intermediate o-alkyl-N-formyltyrosines :are 'thensubjected to .a deformylation reaction by heating with hydrochloricacid solution. The O-alkyltyrosine q-hydrochlorideso produced-isthen esterified in'a standard 'manner,'i.'e.;react1on with acetyl chloride in an'appropriate alcohol to produce the final compounds of this invention.

The preparation of the novel compounds may be illustrated schematically below. whereinR R R and R have the meaning indicated above. 7

. benzyl, phenethyl, etc., and mononuclear heterocyclic;sub-

; stituted lower alkyl radicals such as 'tetrahydrofurfuryl; R is an alkyl radical such as methyl, ethyLxpropyl, butyl,

. hexyl,=etc.; and R and R are members of the groupconsisting of hydrogen atoms, halogen atoms, nitro and,

. amino radicals. With the proviso that when R and R are both hydrogen and R and R are unsubstituted and saturated, the sum of the carbon atoms of R and R is at least seven. The invention also includes the acid addition salts of thecompounds such as the hydrochloride salts.

The compounds of this invention. have. considerable activity against a variety of microorganisms. When tested accordance with the standardagar dilution technique,

the compounds exhibit activity against such "microor-' ganismsas Candida albicans, Saccharomyces carlsbergensis, Mucor ramannianus, Fusarium episphaeria, Hormodendrum cladosporoides, Trichophyton mentagrophytes, Botrytis cinerea, Aspergillus fumigatus, Microsporum gypseum, Penicillium digitatum, Mycobacterium,

--and also against bacterial microorganisms such asthe *mycrococci, for example'Staphylococcus 69, Staphylococcus 'aureus and Sarcina lutea; the streptococci, .for example, Streptococcus 7 No. 11 and Streptococcus 18 No. 80; the bacilli, for example, Bacillus 'subtilis and the mycobacteria, for example, Mycobacterium 607. Sam- 7 plcsof the compounds were prepared in serial dilutions The, invention will bedescribedin greater detail in conjunction with; the following specific examples in which the parts are by weight unless. otherwise specified.

50 EXAMPLE '1 O-ethyl-Njormyl-Lgtyrosine N-formyl L-tyrosine '(510 'parts) was added to a solu- EXAMPLE -2 Following the procedureof the preceding example, the following compounds were prepared: O-methyl-N- formyl'Ltyrosine, 0. n-propylN-formyl-L-tyrosine "(M. v l54-tl56f), -Oat-butyl-N-formyl-L-tyrosine (M. P. 12235 O-n-hcxyl-Niormy1-L;tyrosine.(M. P.

3 EXAMPLE 3 O-methyl-N-formyl-3-nitro-L-tyrosine--- N-formyl-3-nitro-L-tyrosine (38.0 parts) was dissolved in 75 parts by volume of 4 N sodium hydroxidesolution. -To the chilled, stirred solution there was added'in five equal portions 60 parts by volume of 4 N sodium hydroxide solution and 47.6 parts of dimethyl sulfate. The solution was acidified with 8 N nitric acid solution.

T s mi tu e and l parts by volume of acetyl chloride was added. was refluxed until solutionwas complete. The solution was then concentrated under vacuum on a steam bath, leaving a solid residue. This residue was recrystallized from chloroform-ether to give 17.0 parts of purified product melting at 156-157".

EXAMPLE 8 v Q-methyl-L-tyrosine octyl ester hydrochloride gf zgs i $333??? 9 :h i .m i 10 parts of O-methyl-L-tyrosine hydrochloride was Oran 6 melti 0 give par 5 0 an suspended in parts by volume of octyl alcohol, and g Hg 20 parts by volume of acetyl chloride was added. This EXAMPLE 4 mixture was allowed to reflux for five hours, after which Following the procedure of the preceding. example 15 another 10 parts by volume of acetyl chloride was added o methyl N formyl 3 s dfiodo L tymsine (M P 182 and refluxing was continued untll solution was complete. a The reaction solution was then concentrated under 183 was prepared.

vacuum on a steam cone to remove the more volatile E AMPLE 5. material. The resulting solution was then cooled,.and l about parts by volume of etherwas added, causing dmchlor 20 the crude product to precipitate. This material was 0-propyl-N-formyl-L-tyrosine (26.0 parts) was suscollected by filtration and recrystallizedfrom chloroformpended m 400 parts by volume of 3 N hydrochloric acid ether solution, giving 18.3 parts of product melting'at and the mixture was heated on a steam bath until the sus- -122 C. pended solids were in solution. Three parts of activated E PLE 9 charcoal was stirred with the solution for about 10 min- 25 XAM utes, and the mixture was filtered out. The product Following the procedure of Example 8 the compounds crystallized when the filtrate cooled and was collected tabulated, below were prepared. The melting points by filtration. 13.1 parts of product melting at 220-223 C. represent hydrochloride salts. I

R1 R: R: in Name M. 1 o.

' I H O- methyl-L-tyrosine n-hexyl ester. 141-142 H H O-methyl-L-tyroslne cyclohexyl ester 2020-2025 H H O-methyl-L-tyrosiue fi-methylhexyl-I 124-126 H H O-methyl-L-tyroslne n-heptyl ester..- -136. 6 H H O-methyl-L-tyrosine n-oetyl ester 120-122 H O-methyl-L-tyrostne n-nonyl ester.- 130-133 H O-methyl-L-tyrosine n-decyl ester 116-120 H O-methyl-L-tyrosine undecyl ester 131-132 H O-rnethyl-L-tyrostne n-oetadeeyl ester-.- 127-128 H O-methyl-L-tyrosine 2-chloroethyl ester- 207-210 H O-methyl-L-tyrosine 'i-chlorobutyl ester- 164. 5-165. 6 2-methoxyethyl H O-methyl-L-tyrosine 2-methoxyethyl ester. 156-157 tetrahydroiurturyl OH; H O-methyl-L-tyrostns tetrahydrofurt'uryl ester 171-1725 2-(2'-butoxyethoxy)ethyL-- -CH:. H O-mtethyl-L-tyroslne 2-(2-butoxyethoxy)ethyl 148-153 '65 8!. H O-methyl-L-tyrosine benzyl ester 204-205 H O-methyl-L-tyrosine 2-phenylethyl est 172-17316 l H o n-butyl-L-tyrosine n-butyl ester 129. 5-130 H O-n-butyl-L-tyrosine n-amyl ester 129-131 H O-n-propyl-L-wrosine n-butyl ester 132-133 H O-n-propyl-L-tyrosiue n-amyl ester. 131-133 H O-n-propyl-L-tyrosine n-hexyl ester. 134-136 H O-n-hexyl-L-tyrosine n-propyl ester. 139. 5-141 0 H O-n-hexyl-L-tyroslne n-butylesteL- .110-120, H O-n-hexyl-L-tyrosine n-amyl ester 122-121 H -O-nhexyl-L-tyroslne n-hexyl ester: 107-1108, H O-methyl-3-ehloro-L-tyrosine n-butylester 1 179-180 5-1 O-methyl-3,5-diiodo-L-tyrosine n-butyl ester 141-143 5-1 0-methyl-3,5 diiodo-L-tyroslne n-amyl ester 133-134 5-! O-methyl 3,5 dllodo-L-tyrosme n-hesyl ester 127-128 H O-methyl 3 mtr -L-tyrosine n-but'yl ester 95-97. 5 n-butyl H O-methyl 3 amino-L-tyrosine n butyl ester. *225 3,7-dimethyloctyl--. -OH H H O-methyl-L tyrosine-3,7-dimethyloctylester"..- 121-123, fi-methyl-fi-hexenyl. O Hz..... H H O-methyl-L-tyrosine 5-methy1-5-hexenylester... 107-100 (dec.) was obtained. An additional 1.8' parts was EXAMPLE 10 obtained from the concentrated filtrate.

EXAMPLE 6 EXAMPLE 7 O-methyl-L-Iyrosine Z-methoxyet hyl ester hydrochloride 20.0 parts of O-methyI-L-tymsine hydrochloride was suspended in parts by volume of methyl Cellos'olve,

less; yielding a rose temperature was maintained at .of hot 6 N hydrochloricacid and bath for 2 hours.

O-methyl-3-chloro-L-tyrosine hydrochloride To a. solution of 5 parts of O-methyl-N-acetyl-L-tyrosine in 25 parts by volume of acetic acid at 50 was added dropwise 1.8 parts by volume of sulfuryl chloride; The 50-55. Thereafterthe solution was evaporated todryness under reduced pressure. The residue was dissolved in 25 parts by volume heated on the steam Crystals began to separate. The mixture was cooled in an ice-bath. The product was collected on a sintered-glass funnel and washed withice cold 6 N hydrochloric acid until the washings werecolor- I colored solid, -M. P. 225-230;d ec. with sintering at 215. The product was dissolved in 20 parts of hot water and the solution clarifiedwith 1 part of charcoal by heating on the steam bath for ten minutes. To the reheated filtrate there was added 20 parts by volume of 12 N hydrochloric acid. Cooling gave white crystals of the pure product, M. P. 235 dec. with sintering at 215.

We claim:

1. Compounds selected from the group consisting of O-alkyl-L-tyrosine esters of the formula:

wherein R is a member of the group consisting of alkyl radicals, lower alkenyl radicals, lower alkoxy lower alkyl radicals, halo-substituted lower alkyl radicals, cycloalkyl radicals, phenyl lower alkyl radicals, and tetrahydrofurfuryl radical; R is a lower alkyl radical; R and R are members of the group consisting of hydrogen atoms, halogen atoms, nitro and amino radicals with the proviso that when R and R are both hydrogen and R and R are unsubstituted and saturated, the sum of the carbon atoms of R and R is at least seven; and acid addition salts thereof.

. O-methyl-L-tyrosine nonyl ester.

. O-methyl-L-tyrosine octyl ester.

. O-hexyl-L-tyrosine butyl ester.

. O-butyl-L-tyrosine butyl ester.

. O-mcthyl-L-tyrosine decyl ester.

GUI-AWN UNITED STATES PATENT OFFICE CEEFECAT 6F @NZRECTEQN HenryMarcell Kissman et a1x It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should. read. as corrected below.

In the grant, lines 4 and 5', and in the heading to the printed specification, lines 6 and '7, state'of incorporation,

for "a corporation of Delaware" read as a corporation of Maine e Signed and sealed this 25th day of November 1958,

ttest:

KARL H, AXLINE ROBERT C. WATSON Attesting Officer Conmissioner of Patents 

1. COMPOUNDS SELECTED FROM THE GROUP CONSISTING OF O-ALKYL-L-TYROSINE ESTERS OF THE FORMULA: 